Make the marinade

• Combine the cilantro, lime juice, orange juice, soy sauce, cumin, oregano, salt, black pepper, brown sugar and olive oil in a bowl.
• Whisk until the sugar and salt dissolve and the marinade is balanced between acidity, umami and sweetness.

Marinate the steak

• Place the flank steak in the marinade and turn to coat well.
• Cover and refrigerate for as long as you can.

Cook the steak

• Grill the meat outdoors or cook it in a cast iron pan over medium-high heat.
• Cook until it reaches an internal temperature of 135 °F (57 °C).

Rest and slice

• Let the meat rest before slicing.
• Slice against the grain, then cut again with the grain into small bite-size pieces.

Assemble the tacos

• Serve the carne asada in tortillas with guacamole and pico de gallo.